Not quite true. The default behavior changes, and new syntax is added allowing users to specify their desired behavior, but if the sub-query in the CTE does cer

Not quite true. The default behavior changes, and new syntax is added allowing users to specify their desired behavior, but if the sub-query in the CTE does certain things, it will still be materialized instead, regardless. That is: they mostly aren't a fence any more, but can be when you want them to, and sometimes still must be.